2-Dihydromethylpiperazinediium-MII(MII= CuII, FeII, CoII, ZnII) double sulfates and their catalytic activity in diastereoselective nitroaldol (Henry) reaction

2013 ◽  
Vol 42 (2) ◽  
pp. 399-406 ◽  
Author(s):  
Houcine Naïli ◽  
Fadhel Hajlaoui ◽  
Tahar Mhiri ◽  
Tatiana C. O. Mac Leod ◽  
Maximilian N. Kopylovich ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Henry Reaction ◽  
Double Sulfates

Quantitative Evaluation of the Catalytic Activity of Dendrimers with Only One Active Center at the Core:  Application to the Nitroaldol (Henry) Reaction

2004 ◽  
Vol 126 (16) ◽  
pp. 5243-5252 ◽  
Author(s):  
Aizpea Zubia ◽  
Fernando P. Cossío ◽  
Iñaki Morao ◽  
Marina Rieumont ◽  
Xabier Lopez
Keyword(s):  
Catalytic Activity ◽  
Active Center ◽  
Quantitative Evaluation ◽  
Henry Reaction ◽  
The Core

Copper(II) coordination polymers of arylhydrazone of 1H-indene-1,3(2H)-dione linked by 4,4′-bipyridineor hexamethylenetetramine: Evaluation of catalytic activity in Henry reaction

Polyhedron ◽  
2017 ◽  
Vol 133 ◽  
pp. 33-39 ◽  
Author(s):  
Gonçalo A.O. Tiago ◽  
Kamran T. Mahmudov ◽  
M. Fátima C. Guedes da Silva ◽  
Ana P.C. Ribeiro ◽  
Fatali E. Huseynov ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Coordination Polymers ◽  
Henry Reaction

scholarly journals Azo-dimethylaminopyridine-functionalized Ni(II)-porphyrin as a photoswitchable nucleophilic catalyst

2020 ◽  
Vol 16 ◽  
pp. 2119-2126
Author(s):  
Jannis Ludwig ◽  
Julian Helberg ◽  
Hendrik Zipse ◽  
Rainer Herges
Keyword(s):  
Catalytic Activity ◽  
Spin State ◽  
Rate Constants ◽  
Green Light ◽  
Lone Pair ◽  
Henry Reaction ◽  
Record Player

We present the synthesis and the photochemical and catalytic switching properties of an azopyridine as a photoswitchable ligand, covalently attached to a Ni(II)-porphyrin. Upon irradiation with 530 nm (green light), the azopyridine switches to the cis configuration and coordinates with the Ni2+ ion. Light of 435 nm (violet) isomerizes the ligand back to the trans configuration, which decoordinates for steric reasons. This so-called record player design has been used previously to switch the spin state of Ni2+ between singlet and triplet. We now use the coordination/decoordination process to switch the catalytic activity of the dimethylaminopyridine (DMAP) unit. DMAP is a known catalyst in the nitroaldol (Henry) reaction. Upon coordination to the Ni2+ ion, the basicity of the pyridine lone pair is attenuated and hence the catalytic activity is reduced. Decoordination restores the catalytic activity. The rate constants in the two switching states differ by a factor of 2.2, and the catalytic switching is reversible.

scholarly journals Azo-dimethylaminopyridine functionalized Ni(II)-Porphyrin as a Photoswitchable Nucleophilic Catalyst

2020 ◽  
Author(s):  
Jannis Ludwig ◽  
Julian Helberg ◽  
Hendrik Zipse ◽  
Rainer Herges
Keyword(s):  
Catalytic Activity ◽  
Spin State ◽  
Rate Constants ◽  
Green Light ◽  
Lone Pair ◽  
Henry Reaction ◽  
Record Player

We present the synthesis and the photochemical and catalytic switching properties of an azopyridine as a photoswitchable ligand, covalently attached to a Ni(II)-porphyrin. Upon irradiation with 530 nm (green light), the azopyridine switches to the cis configuration and coordinates with the Ni2+ ion. Light of 435 nm (violet) isomerizes the ligand back to the trans configuration, which decoordinates for steric reasons. This so-called record player design has been used previously to switch the spin state of Ni2+ between singlet and triplet. We now use the coordination/decoordination process to switch the catalytic activity of the dimethylaminopyridine (DMAP) unit. DMAP is a known catalyst in the nitroaldol (Henry) reaction. Upon coordination to the Ni2+ ion, the basicity of the pyridine lone pair is attenuated and hence the catalytic activity is reduced. Decoordination restores the catalytic activity. The rate constants in the two switching states differ by a factor of 2.2, and the catalytic switching is reversible.

CoII, NiII and UO2II complexes with β-diketones and their arylhydrazone derivatives: Synthesis, structure and catalytic activity in Henry reaction

Polyhedron ◽  
2015 ◽  
Vol 101 ◽  
pp. 14-22 ◽  
Author(s):  
Zhen Ma ◽  
Manas Sutradhar ◽  
Atash V. Gurbanov ◽  
Abel M. Maharramov ◽  
Rafiga A. Aliyeva ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Henry Reaction

scholarly journals Νέοι οργανοκαταλύτες και εφαρμογές τους σε ασύμμετρους οργανικούς μετασχηματισμούς

2014 ◽  
Author(s):  
Μιχαήλ Τσάκος
Keyword(s):  
Catalytic Activity ◽  
Asymmetric Catalysis ◽  
Primary Amine ◽  
Aldol Reactions ◽  
Henry Reaction ◽  
Asymmetric Aldol ◽  
Asymmetric Transformations ◽  
Tert Butyl ◽  
Proline Derivatives ◽  
Asymmetric Michael Reaction

Nowadays, organocatalysis constitutes the third pillar of asymmetric catalysis, alongside transition metal catalysis and biocatalysis. The definition of organocatalysis is the use of low molecular weight organic molecules as catalysts in organic transformations.The goals of this thesis were on one hand, to synthesize novel organocatalysts based on natural aminoacids and evaluate their activity in known asymmetric transformations, and on the other hand, to exploit organocatalysis in general in order to accomplish unprecedented asymmetric reactions.In the context of synthesizing novel organocatalysts, we synthesized primary amine-thioureas based on di-tert-butyl aspartate and a chiral 1,2-diamine and we studied their catalytic activity in the asymmetric Michael reaction between ketones and nitroalkenes or nitrodienes. Σhe primary amine-thiourea consisting of di-tert-butyl aspartate and (1R, 2R)-diphenylethylene-1,2-diamine, was found to be a very powerful organocatalyst exhibiting remarkable results in the asymmetric Michael addition of methyl ketones to nitroalkenes or nitrodienes. The aforementioned organocatalyst was employed in the key-step of the asymmetric synthesis of the commercially available drug Baclofen.In addition, organocatalysts known in the literature were employed in order to develop unprecedented asymmetric transformations, such as the domino Michael-Henry reaction between 1,4-cyclohexanedione and nitroalkenes and the asymmetric Mannich addition of 2-chloro-1,3-dicarbonyl compounds or nitroalkanes to oxindole derived ketimines.Furthermore, a segment of this thesis focused on the synthesis of proline derivatives properly modified for immobilization on carbon nanotubes, in order to evaluate their catalytic activity in asymmetric aldol reactions.

scholarly journals Co–salen complexes as catalysts for the asymmetric Henry reaction – reversed enantioselectivity through simple ligand modification

RSC Advances ◽  
2015 ◽  
Vol 5 (37) ◽  
pp. 29108-29113 ◽  
Author(s):  
J. Dimroth ◽  
M. Weck
Keyword(s):  
Schiff Base ◽  
Catalytic Activity ◽  
Henry Reaction ◽  
Ligand Modification ◽  
Salen Complexes ◽  
Reduced Schiff Base ◽  
Cyclic Oligomers ◽  
Derivatives Of

Derivatives of Co-salen catalysts were tested in the asymmetric Henry reaction. Cyclic oligomers displayed a higher catalytic activity than their monomeric counterparts, and reduced Schiff-base versions showed a reversed enantioselectivity.

Sign in / Sign up

Export Citation Format

Share Document